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46-480 Power Transformer Vibrates
#16

Thanks folks! Through pure diligence and the help of a Philco expert I was able to get this radio up and running like it should be.

Johnny

"It's Nice To Be Nice To The Nice"
Major Frank Burns Mash 4077th
#17

Johnny, this is the "learning channel". Don't keep us in suspense. Tell us what the problem was!
Jerry

A friend in need is a pest!  Bill Slee ca 1970.
#18

I am curious about this one, too. From my work in Class-A solid state amps, transformers hum/buzz/vibrate as the load on them increases beyond their "happy point", thus I would have recommended looking at your PS caps and resistors to ground. It would have been interesting to experiment with resistor values in the range of 20k to 50k (difference between what you have and the spec sheet).

So, what was the trick?
#19

Let me clear up the "Vibrating Transformer" first. Only had two screws holding it onto the chassis. Added two more and it's gone.

And Jerry I read your reply on the 16th. It was my birthday (a big 60 now) and it was a pleasant day until around 5:30pm when my computer said there were Windows updates ready and I said update it. Last thing to do when it was done was to restart the computer. So I clicked the restart now button and I haven't had a computer since. And after over $1,300 of real nice new computer equipment I find that the only thing that died was my old monitor. Some technician eh?

So not only am I getting used to a whole new computer but Win8 too. Jumped here from WinXP Home. But I'm getting there. I did have my old machine backed up to an external 1TB drive and I had just backed up my QuickBooks data to a thumb drive the day before.

But lets talk Philco 46-480.

I'll make it easy. On the piece of schematic below (RF Section) the red lines indicate the way it should be. I added the purple lines to indicate the way I put it back together.
[Image: http://speakeasyradios.com/yahoo_site_ad...26_std.jpg]

Fixed this and the radio worked great for the amount of time it took to perform a complete AM and FM alignment. I let it play for about three hours after that, going out to the shop to check it every once and a while. Last time I went out FM was dead again. It won't even allow me to align the FM. Whole circuit's dead. So something opened up and I'm not going looking for it. Over 140 hours along with replacing everything in this boat anchor? Exactly what I'm going to use it for. Time to move on.

Johnny

"It's Nice To Be Nice To The Nice"
Major Frank Burns Mash 4077th
#20

I feel the pain Johnny and Happy Birthday. Let it set for a while, you can always come back to it later.
Jerry

A friend in need is a pest!  Bill Slee ca 1970.




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